The integration of structural health monitoring (SHM) systems into in-service applications has been hindered by the implied infrastructure, specifically wires for power and data from each sensor an acquisition and/or processing unit. Prior research by the present investigators has demonstrated a patented method of point-of-measurement datalogging for SHM, thereby greatly reducing the required quantity of cable by locally converting analog signals into digital data that can be placed on a common sensor-bus. During the present research, this efficient architecture is further enhanced by exploiting direct-write (DW) technologies to produce a cable-free digital sensor-bus. This concept has broad implications particularly for large area composite structures, where significant weight reductions and durability gains can be achieved by replacing traditional instrumentation.
To date, DW technology has been demonstrated to successfully power and transfer data from analog sensor arrays, however the present work aims to extend the DW portfolio to include digital communication. Research was conducted in several areas in order to achieve this goal, including ensuring compatibility with existing practical SHM hardware and methods, as well as the optimization of geometric and electrical parameters. Finally, a proof-of-concept experiment has been designed to demonstrate the integration of all the described system elements to detect and localize damage on a composite plate.